iMac G5 RevB Won't Start HELP!!!

N10248 said:

HELP!

My iMac G5 RevB (full spec in signature) just cut out, i thought it was a power cut at first but its not now it wont start,
it gets half way though the chime and cuts out completely.

I've tried resetting the SMU and no change i cant reset the PRAM because it cant even make a whole chime now.

Ive had a look inside, no weird smells or nothing other noticably wrong, no new ram has been added (Still the stock 512mb)

also no apple care and the closest apple store is the london one. so i dont want to have to take it there and spend a fortune on a new psu or something until i know whats wrong.

Any ideas????? anyone?

i'm stuck on my G3 Clamshell now ARRRGGGHHHH!!!!

Click to expand...

I had the same problem. Replaced the PSU and it works fine now (since January).

Take the back cover off and locate the internal power switch (look for a big white arrow) and the four diagnostic LEDs. Press the button and see which LEDs light up... this should give you some indication as to whether the problem is the power supply or logic board etc.


LED 1 indicates that trickle voltage from the power supply has been detected. This LED will be ON when the computer is turned off and your power supply is working correctly.

LED 2 indicates that the main logic board has detected proper power from the power supply when the computer is turned on. This LED will be ON when the computer is turned on and the power supply is working correctly.

LED 3 indicates that the computer and the LCD display are communicating. This LED will be ON when the computer is turned on and video signal is being generated.

LED 4 lights only if the computer detects an over-temperature condition. This LED will be OFF when the computer is turned on and running at the correct temperature.

N10248 said:

ive took the back off the 1st LED is on as soon as the main power is on, i press the internal power button and the motors start and the second light comes on it gets to the chime and then turns off,

the screen would kick in a few seconds later and it has managed to get the grey apple logo up a couple of times so i think the screen is ok

HERE is a video i took with my phone to show what happens.

so far according to some posts on the apple suport site it seems it is the psu, but the fact that it is starting at all means it hasnt burnt out or something.

Click to expand...

Hmmm, yours gets further than my broken iMac G5 (also a Rev B) then.

Mine crapped out over 2 months ago now, I just haven't found time to take it in for repair.

Here's the video I posted of mine. There's a funny squeaking sound coming from that second LED which just occasionally flashes when the power supply is connected. Mine doesn't start up at all.

Have you checked your original purchase date? The Rev Bs came out around mid-2005 so you might find you've still got a few days of warranty left if you're lucky. Hope you manage to get it repaired.